KRASNAYA POLYANA, Russia (AP) -- Britain's Lizzy Yarnold won the season's first race on a technicality.

The season's last race, there was no argument.

Yarnold won the Olympic women's skeleton gold medal Friday night, a victory that puts the 25-year-old unquestionably atop her sport, probably for years to come. Her four-run time was 0.97 seconds faster than silver medalist Noelle Pikus-Pace of Eagle Mountain, Utah, who entered retirement by exorcising the memory of letting a medal slip away in Vancouver four years ago.

"It won't sink in for a few more days, but I'm over the moon," Yarnold said, as a full moon illuminated part of the Russian night sky. "I'm so proud. I put in all the work for five years and it all worked out."

Yarnold, who also won the World Cup overall title this season, claimed Britain's first gold at the Sochi Games. Her time was 3 minutes, 52.89 seconds, and the final trip down the track was a mere formality, given that she already had a 0.78-second edge over Pikus-Pace and only needed to avoid a giant mistake.

It didn't happen. The fourth run was like all the others -- flawless.

She grabbed a British flag, hopped near the finish line, embraced teammate Shelley Rudman and seemed to just never stop smiling.

"Lizzy's been a beautiful bubble of confidence in every one of her races," said Amy Williams, the 2010 skeleton gold medalist from Britain. "I'm so proud of her that we kept the medal in Great Britain and wrote ourselves into the history books."

Pikus-Pace insisted that this time, she'll retire happy. Simply being in the Olympic race was victory enough; Pikus-Pace revealed afterward that she was dealing with concussion-like symptoms for several days before the race and minimized her training time on the advice of doctors.

"I felt fine and safe sliding but my vision has been going in and out of being able to focus, which slows my reaction time," Pikus-Pace said. "It has been an extremely difficult week but my family, coaches, and prayers of many allowed me to come out and compete the best I can given the situation."

Elena Nikitina of Russia won the bronze, another 0.44 seconds off the pace and just 0.04 seconds ahead of Katie Uhlaender of Breckenridge, Colo., who took fourth for her top Olympic finish.

And afterward, Uhlaender wasn't lamenting coming so close. Instead, she picked up Pikus-Pace's daughter Lacee, gave her an embrace and sang her teammate's praises.

"I couldn't be more proud of her," Uhlaender said. "This is a great last race for us both. Noelle finished fourth last time and now she's on the podium and I couldn't be happier for her."

The Lizzy-vs.-Noelle rivalry was back and forth all season, starting with the World Cup opener in Calgary, where Pikus-Pace crossed the line first and was originally announced as the winner. But Yarnold was awarded the victory after race officials said the American used too much tape on the handle of her sled.

That decision played a huge role in deciding the World Cup title. From there, Pikus-Pace set her sights on closing out her sliding career with an Olympic medal -- which is really the only thing that lured her from retirement two years ago, especially since a trip to the podium in Vancouver was lost when she made a mistake in Curve 2 of her final run at the 2010 Olympics.

"This is a dream come true for myself and my family," Pikus-Pace said. "Absolutely unbelievable. I stood up there at the start knowing this was my race and I knew I was just going to go for it."

When she crossed the line Friday night, knowing hardware was hers, she flashed a megawatt smile. Retirement, she said, would be about spending time with her family. She couldn't wait to get started, hopping over the track wall to join her husband and children for hugs and kisses -- her first, ever, as an Olympic medalist.

Then she waved to fans.

Waving goodbye, essentially.

Yarnold, she's basically just saying hello.

She announced herself as the next big thing in skeleton two winters ago, winning two of her first four World Cup races. A year ago, she vaulted to No. 4 in the World Cup rankings, and inconsistency kept her from rising even higher.

This season, she figured it all out. World Cup champion. Olympic champion. And her top rival is retiring.

Yarnold covered her face, almost in disbelief, on the flower podium afterward. Pikus-Pace wept softly through her smile and was the last to leave the stand, seeming almost unsure where to go next.